1. Field of the Invention
The present invention relates to a device for mixing when required for use a liquid solvent with either a solid or liquid substance to be dissolved in the solvent, storing the solution thus obtained and dispensing under sterile conditions dosed amounts of the solution.
The present invention specifically tackles the problem of extemporaneously preparing and dispensing dosed amounts of pharmaceutical preparations which result from the extemporaneous mixing of a liquid solvent, which is kept in a first container, with a pharmaceutical substance or drug in powder or liquid form, kept in a second container, the pharmaceutical substance being mixed with or dissolved in the solvent when required for use.
2. Description of the Prior Art
There are known the difficulties which are often encountered when a liquid (e.g. a solvent) kept in a first sealed container is to be transferred under aseptical conditions into a second container which is also sealed, wherein a substance in solid or liquid form is placed. This situation occurs particularly in the pharmaceutical art wherein solutions, suitable for intravenous or oral administration are often extemporaneously prepared directly by the user by mixing a liquid solvent with a liquid or solid pharmacologically active agent, both the solvent and the active agent being stored separately in distinct containers up to the moment of mixture preparation.
Several devices have been disclosed, which are provided with pumping means for carrying out under aseptical conditions the transfer of a liquid solvent from a first sealed container into a second sealed container. These devices are costly and cumbersome and frequently do not afford satisfactory results.
It has been also proposed to keep one of the containers under vacuum, so that the vacuum causes, when the containers are connected to each other by means of a double-tipped, hollow needle inserted through the rubber plugs of both containers placed in superimposed relationship, the passage of the liquid solvent to occur from the container at atmospheric pressure into the container under vacuum. Also these arrangements have proved to be costly and cumbersome.